Unlocking the Potential of Cassava

About

The Next Generation Cassava Breeding (NEXTGEN Cassava) project aims to significantly increase the rate of genetic improvement in cassava breeding and unlock the full potential of cassava, a staple crop central to food security and livelihoods across Africa. The project will implement and empirically test a new breeding method known as Genomic Selection that relies on statistical modeling to predict cassava performance before field-testing, and dramatically accelerates the breeding cycle.

NEXTGEN Cassava will invest in human and infrastructure capacity at partner breeding programs; develop methods to increase flowering and seed set in cassava; create a database (www.cassavabase.org) centralizing information tracking, genotypic and phenotypic data, and Genomic Selection prediction analyses; enhance cassava germplasm exchange between Latin American and Africa; and support the establishment of a biotechnology/biosafety outreach and training hub at the National Crops Resources Research Institute (NaCRRI) in Uganda.

NextGen is led by International Programs in the College of Agriculture and Life Sciences at Cornell University, in collaboration with the International Institute of Tropical Agriculture and National Root Crops Research Institute breeding centers in Nigeria, the National Crops Resources Research Institute in Uganda, Tanzania’s Ministry of Agriculture, Livestock, and Fisheries, the West African Centre for Crop Improvement in Ghana, Makerere University in Uganda, and the Boyce Thompson Institute, USDA-ARS, and the U.S. Department of Energy in the United States. NEXTGEN Cassava is supported by the Bill & Melinda Gates Foundation and the UK Department for International Development.

Why cassava?

Cassava (Manihot esculenta), a major staple crop, is the main source of calories for 500 million people across the globe. A perennial woody shrub native to Latin America, cassava is primarily grown as an annual crop in the humid tropics. A cash crop as well as a subsistence crop, cassava's large edible starchy roots are a source of low-cost carbohydrates for millions. Cassava end products range from fresh roots cooked, boiled, baked or fried at the household level, to highly processed starch as a food additive.

Characteristics such as low input requirements, resistance to drought, ability to grow in marginal soils and long-term storability of the roots in the ground, make cassava a truly resilient crop for food security. Studies indicate cassava stands to be the only staple crop that stands to benefit from climate change. As more land is rendered unusable due to changing temperature and rainfall patterns, cassava looks to gain importance as a staple around the globe.

Cassava roots are processed and eaten by 500 million people a day in Africa, where it is a staple for 40% of the population. Photo courtesy of Hale Tufan, Cornell University.

Cassava is important for food security in Africa

No other continent depends on cassava to feed as many people as does Africa, where 500 million people consume it daily. Africa's small farmers produce more than half of the world's cassava, or about 86 million tons from over 10 million hectares. On the continent, where 40% of the population consumes cassava as a staple crop, cassava is the second most important staple crop after maize. Cassava is indispensable to food security in Africa. It is a widely preferred and consumed staple, as well as a hardy crop that can be stored in the ground as a fall-back source of food that can save lives in times of famine. Despite the importance of cassava for food security on the African continent, it has received relatively little research and development attention compared to other staples such as wheat, rice and maize. The key to unlocking the full potential of cassava lies largely in bringing cassava breeding into the 21st century.

Re-imagining Cassava Breeding

At the Plant and Animal Genomes conference in 2011, cassava breeders and researchers were consulted on how they would 're-imagine' cassava breeding. What would they change to enhance cassava breeding?

NEXTGEN Cassava emerged from this consultation, to address the action points identified:

Shorten the cassava breeding cycle. Cassava breeding is a lengthy process- it can take up to a decade to release new varieties. Shorter breeding cycles would allow breeders to respond to changing breeding targets, and meet the demands of smallholder farmers.

Improve cassava flowering and seed set. Many cassava genotypes flower poorly, if at all. If they do not flower, they cannot be used in crossing. So, some very promising cassava lines cannot then be used in breeding programs. Improved flowering and seed set would allow breeders to fully mobilize the genetic resources in their cassava breeding programs.

Enable greater germplasm exchange. Cassava originates from Latin America. The genetic diversity present at the center of origin could provide cassava breeders in Africa with access to genetic resources to diversify their breeding programs and meet their breeding goals. Facilitating greater germplasm exchange would have great impact on generating new cassava varieties for Africa.

Improve information exchange. Increasing research attention to cassava has resulted in a greater number of projects producing large quantities of phenotypic and genotypic information. A platform to facilitate communication and data exchange between cassava researchers and breeders would greatly help to harmonize cassava research across the globe.

CassavaBase

Access to data and tools for breeders and researchers, including genomic selection algorithms and analysis capacity, a cassava genome browser, cassava ontology tools, phenotyping tools, and social networking.